Active sensing using light, or active photolocation, is only known from deep sea and nocturnal fish with chemiluminescent 'search' lights. Bright irides in diurnal fish species have recently been proposed as a potential analogue. Here, we contribute to this discussion by testing whether iris radiance is actively modulated. The focus is on behaviourally controlled iris reflections, called 'ocular sparks'. The triplefin Tripterygion delaisi can alternate between red and blue ocular sparks, allowing us to test the prediction that spark frequency and hue depend on background hue and prey presence...

In this study, we maneuvered a dual-band spectral imaging system to capture an iridal image from a cosmetic-contact-lens-wearing subject. By using the independent component analysis to separate individual spectral primitives, we successfully distinguished the natural iris texture from the cosmetic contact lens (CCL) pattern, and restored the genuine iris patterns from the CCL-polluted image. Based on a database containing 200 test image pairs from 20 CCL-wearing subjects as the proof of concept, the recognition accuracy (False Rejection Rate: FRR) was improved from FRR = 10...

The honeycomb lattice is one of the simplest lattice structures. Electrons and spins on this simple lattice, however, often form exotic phases with non-trivial excitations. Massless Dirac fermions can emerge out of itinerant electrons, as demonstrated experimentally in graphene, and a topological quantum spin liquid with exotic quasiparticles can be realized in spin-1/2 magnets, as proposed theoretically in the Kitaev model. The quantum spin liquid is a long-sought exotic state of matter, in which interacting spins remain quantum-disordered without spontaneous symmetry breaking...

Effects of spin-orbit interactions in condensed matter are an important and rapidly evolving topic. Strong competition between spin-orbit, on-site Coulomb and crystalline electric field interactions in iridates drives exotic quantum states that are unique to this group of materials. In particular, the "Jeff = ½" Mott state served as an early signal that the combined effect of strong spin-orbit and Coulomb interactions in iridates has unique, intriguing consequences. In this Key Issues Review, we survey some current experimental studies of iridates...

Contiguous microdeletions of the Norrie disease pseudoglioma (NDP) region on chromosome Xp11.3 have been widely confirmed as contributing to the typical clinical features of Norrie disease (ND). However, the precise relation between genotype and phenotype could vary. The contiguous deletion of NDP and its neighbouring genes, MAOA/B and EFHC2, reportedly leads to syndromic clinical features such as microcephaly, intellectual disability, and epilepsy. Herewe report a novel contiguous microdeletion of the NDP region containing the MAOB and EFHC2 genes,which causes eye defects but no cognitive disability...

The magnetic properties of the pyrochlore iridate material Eu_{2}Ir_{2}O_{7} (5d^{5}) have been studied based on first principles calculations, where the crystal field splitting Δ, spin-orbit coupling (SOC) λ, and Coulomb interaction U within Ir 5d orbitals all play significant roles. The ground state phase diagram has been obtained with respect to the strength of SOC and Coulomb interaction U, where a stable antiferromagnetic ground state with all-in-all-out (AIAO) spin structure has been found. In addition, another antiferromagnetic state with energy close to AIAO has also been found to be stable...

Тhe prevalence of complications associated with the deficiency or absence of capsular support in cataract patients is 5-15%. Moreover, approximately 20% of patients have an inconspicuous zonular weakness, which is often left undetected preoperatively. AIM: to classify and comparatively analyze the latest published data on the outcomes of various kinds of complicated cataract surgery. MATERIAL AND METHODS: Analysis of available literature on the subject of research published in 2003-2016...

BACKGROUND: The microbiota of the bovine upper respiratory tract has been recently characterized, but no data for the lower respiratory tract are available. A major health problem in bovine medicine is infectious bronchopneumonia, the most common respiratory syndrome affecting cattle. With this study, we used 16S rRNA gene sequencing to characterize and compare the microbial community composition of the upper and lower respiratory tracts in calves. RESULTS: The microbiota of the upper (nasal swab [NS]) and the lower (trans-tracheal aspiration [TTA]) respiratory tracts of 19 post-weaned Piedmontese calves with (8/19) and without (11/19) clinical signs of respiratory disease, coming from six different farms, was characterized by 16S rRNA gene metabarcoding...

A micro-plenoptic system was designed to capture the three-dimensional (3D) topography of the anterior iris surface by simple single-shot imaging. Within a depth-of-field of 2.4 mm, depth resolution of 10 µm can be achieved with accuracy (systematic errors) and precision (random errors) below 20%. We demonstrated the application of our micro-plenoptic imaging system on two healthy irides, an iris with naevi, and an iris with melanoma. The ridges and folds, with height differences of 10~80 µm, on the healthy irides can be effectively captured...

BACKGROUND: Grass pollen-related seasonal allergic rhinoconjunctivitis (SARg) is clinically heterogeneous in severity, comorbidities and response to treatment. The component-resolved diagnostics disclosed also a high heterogeneity at molecular level. Our study aimed at analyzing the characteristics of the IgE sensitization to Phleum pratense molecules and investigating the diagnostic relevance of such molecules in childhood. METHODS: We examined 1120 children (age 4-18y) with SARg...

The rainbow has been the subject of discussion across a variety of historical periods and cultures, and numerous optical explanations have been suggested. Here, we further explore the scientific treatise De iride [On the Rainbow] written by Robert Grosseteste in the 13th century. Attempting to account for the shape of the rainbow, Grosseteste bases his explanation on the optical properties of transparent cones, which he claims can give rise to arc-shaped projections through refraction. By stating that atmospheric phenomena are reducible to the geometric optics of a conical prism, the De iride lays out a coherent and testable hypothesis...

Magnetic honeycomb iridates are thought to show strongly spin-anisotropic exchange interactions which, when highly frustrated, lead to an exotic state of matter known as the Kitaev quantum spin liquid. However, in all known examples these materials magnetically order at finite temperatures, the scale of which may imply weak frustration. Here we show that the application of a relatively small magnetic field drives the three-dimensional magnet β-Li2IrO3 from its incommensurate ground state into a quantum correlated paramagnet...

We present the first copper iridium binary metal oxide with the chemical formula Cu2IrO3. The material is synthesized from the parent compound Na2IrO3 by a topotactic reaction where sodium is exchanged with copper under mild conditions. Cu2IrO3 has the same monoclinic space group (C2/c) as Na2IrO3 with a layered honeycomb structure. The parent compound Na2IrO3 is proposed to be relevant to the Kitaev spin liquid on the basis of having Ir(4+) with an effective spin of 1/2 on a honeycomb lattice. Remarkably, whereas Na2IrO3 shows a long-range magnetic order at 15 K and fails to become a true spin liquid, Cu2IrO3 remains disordered until 2...

A powder sample of pure H3LiIr2O6 was synthesized from α-Li2IrO3 powder by a soft chemical replacement of Li(+) with H(+). The crystal structure of H3LiIr2O6 consists of sheets of edge sharing LiO6- and IrO6-octahedra forming a honeycomb network with layers stacked in a monoclinic distorted HCrO2 type pattern. Heavy stacking faulting of the sheets is indicated by anisotropic peak broadening in the X-ray powder diffraction (XRPD) pattern. The ideal, faultless crystal structure was obtained by a Rietveld refinement of the laboratory XRPD pattern while using the LiIr2O6(3-)-layers of α-Li2IrO3 as a starting model...

Kitaev's honeycomb lattice spin model is a remarkable exactly solvable model, which has a particular type of spin liquid (Kitaev spin liquid) as the ground state. Although its possible realization in iridates and α-RuCl_{3} has been vigorously discussed recently, these materials have substantial non-Kitaev direct exchange interactions and do not have a spin liquid ground state. We propose metal-organic frameworks (MOFs) with Ru^{3+} (or Os^{3+}), forming the honeycomb lattice as promising candidates for a more ideal realization of Kitaev-type spin models, where the direct exchange interaction is strongly suppressed...

The resemblance of crystallographic and magnetic structures of the quasi-two-dimensional iridates Ba2IrO4 and Sr2IrO4 to La2CuO4 points at an analogy to cuprate high-Tc superconductors, even if spin-orbit coupling is very strong in iridates. Here we examine this analogy for the motion of a charge (hole or electron) added to the antiferromagnetic ground state. We show that correlation effects render the hole and electron case in iridates very different. An added electron forms a spin polaron, similar to the cuprates, but the situation of a removed electron is far more complex...

Iritectol G, a novel iridal-type triterpenoid containing an uncommon tetrahydrofuran moiety, was isolated from the rhizomes of Iris tectorum. The structure was elucidated by comprehensive spectroscopic analysis. Iritectol G inhibited spontaneous and 4-aminopyridine-evoked calcium oscillations in primary cultured neocortical neurons with IC50 values of 8.2μM and 12.5μM, respectively. Further electrophysiological study demonstrated that iritectol G preferred to interact with inactivated state of voltage-gated sodium channel with an IC50 value of 7...